1. Field
The present disclosure relates to a multidirectional vibration generator using a single vibrator and its vibration generating method, and more particularly, to a single vibrator multidirectional vibration haptic feedback device giving a vibration effect with multidirectional frequencies according to a frequency of a driving source and a method for giving a haptic effect using a single vibrator.
2. Description of the Related Art
Generally, haptic feedback allows a user to feel sense of touch, force, motion or the like by means of a keyboard, a mouse, a joystick, a touch screen or the like. In particular, the technique in relation to touch feedback using the sense of touch on the skin may be relatively easily implemented, and this is widely applied to touch control interfaces of portable devices such as cellular phones, PDA or the like. In addition, the touch feedback improves the feeling of manipulation to a device and also gives the sense of reality and immersion to a user, and thus various techniques capable of implementing various kinds of touches are being developed.
In this tendency, many attempts are being made to diversify vibration effects of a vibration generating device, and particularly it is needed to develop a multi-mode vibration generating device capable of giving vibrations having a plurality of frequencies to a vibration generating device.
FIG. 9 shows an example of a general haptic feedback device. The general haptic feedback device depicted in FIG. 9 uses four vibrators 201, 202, 203, 204. If a specific point 200 is touched by a user, a width 211, 212 and a height 213, 214 are measured and calculated based on the touched specific point 200, so that the vibrators 201, 202, 203, 204 have different values depending on a touched location.
However, this device uses a plurality of vibrators 201, 202, 203, 204, and thus it is difficult to design the entire device or system in a small size.
In addition, FIG. 10 shows another example of a general haptic feedback device. The haptic feedback device depicted in FIG. 10 includes an input unit 301, a control unit 304, a vibrator driving unit 305, a first vibrator 302, and a second vibrator 303. The first vibrator 302 and the second vibrator 303 may vibrate to generate a vibration stimulus when a driving signal of the vibrator driving unit 305 varies.
Moreover, in this device, vibration stimuli generated at specific frequencies of first and second vibrators are synthetically exhibited as shown in FIG. 11. In other words, the synthetic vibration of the first vibrator 302 and the second vibrator 303 are shown as the sum of vibrations of a vibration frequency having an absolute value (|f1-f2|) which is a difference between a first vibration frequency (f1) and a second vibration frequency (f2) and vibrations of a frequency having a mean value ((f1+f2)/2) of the first vibration frequency (f1) and the second vibration frequency (f2).
However, as shown in FIG. 11, in this device, a vibration desired by a user may not be easily generated other than the vibrations of a vibration frequency having an absolute value (|f1-f2|) which is a difference between the first vibration frequency (f1) and the second vibration frequency (f2) and the vibrations of a frequency having a mean value ((f1+f2)/2) of the first vibration frequency (f1) and the second vibration frequency (f2), and even though vibrations are generated, their magnitudes are very small.
In addition, since two vibrators are used as described above, it is still difficult to design the entire device or system in a small size.
Next, FIG. 12 shows another example of a general haptic feedback device, which particularly includes a single vibration driving unit. In other words, this device includes an electromagnetic circuit 404 for receiving a driving power and generating an electromagnetic force, a driving unit 403 disposed at an upper portion of the electromagnetic circuit to vibrate in a plurality of vibration frequencies according to the frequency of the driving power, and a case unit 400 surrounding the electromagnetic circuit and the driving unit.
However, this device also includes two vibration modes (for example, an x-axis mode and a y-axis mode) having different inherent vibration frequencies f1 and f2 as shown in FIG. 13 so that a vibration effect is implemented with a waveform where f1 and f2 are synthesized. In addition, a vibration desired by a user may not be easily generated other than the inherent vibration frequencies, and even though vibrations are generated, their magnitudes are very small.